I'm tetraplegic, require hoist to get in/out of bed to electric chair. Is it possible to manouvre around ship, are hoists provided in cabin,can mobile gantry hoist be put over bed,is room in cabin big for turning,can chair be charged in cabin,can I be tendered in chair,are taxis available to sightsee that I will be able to use once in chair I'm in it all day.can I use shower chair or bed bath etc etc

I am not sure about the equipment the cruise companies provide for your situation. However, I have seen electric chairs being recharged on ships - usually in the passageways, although in-cabin charging may be available - and I have seen those in electric chairs tendering ashore and otherwise enjoying themselves.

I recall cruising on the Celebrity Century a few years ago and seeing two young men who were tetraplegic. They got around quite well. As I recall, they had to control their chairs via puffs of air.

Wheelchairs can certainly cruise. The ships are usually very easy to get around on - the best have automatic doors throughout. The difficulty starts when you disembark at ports of call. You'll sometimes find ramps, other times you'll have to be carried down steps. Tenders may be accessible, maybe not. And w/c accessible excursions are rare (I've found private tours in San Juan, St. Thomas, Costa Rica). I personally don't think the industry likes us much (we need bigger cabins, special lifts, etc.). They do very litte to encourage w/c users, but that being said, you'll find the ship personnel VERY helpful in overcoming the barriers. Handicap rooms are spacious, and charging my w/c just means plugging it in same as in any hotel room. As for a bed lift, I don't use one so don't know - check with the cruise line. So far I like Royal Caribbean best. Their private peninsula Labadee is easily tendered and hard-packed sand.

No cruise lines provide lifts or other special equipment except for raised toilet seats. We take the following when cruising:

Power wheelchair and charger

Manual wheelchair for back-up and any tender ports

Travel shower/commode chair for the roll-in shower and over toilet (less transfers)

Travel lift

Slide board for getting into cabs or rental cars ashore[/list]
You can rent equipment through companies such as Carevacations.com if you need a hospital bed or lift and don't want to bring your own with you.

If I were you I would try Alaska for my first cruise for one huge reason. ADA. The USA is the only country in the world who has it, and while the US based cruise ships are now designed pretty much with disabilities in mind, and close to ADAAG requirements, (I saw minor non-compliance issues on the Princess Diamond when she was new 2 years ago, but I'm an architect with a specialty in ADA)the ports in other countries are definitely NOT accessible. Most of the ports of call for the Alaska cruise are on US soil, so they have to be accessible by law. I didn't get off the ship in Victoria so I can't say if that port has been adjusted, but my guess is that is has been.
As for the Alaskan port excursions, you can definitely take the tram to Mt Robert in Juneau, or the 1898 train up the mountain in Skagway, and there are lots of things and shopping right at the dock in Ketchikan. There is no tendering at the Alaskan ports, at least for Princess.
When we docked in Ketchikan, the ramp down from the Plaza level was not 1:12 so it was too steep for a wheelchair. I saw where there was another gangway coming from a much lower deck for wheelchairs to have access. Hopes this helps.